Recently, attention has been focused on semiconductor memories that use, as a memory device, a nonvolatile memory such as a resistance change memory (e.g., a magnetoresistive random access memory: MRAM, a phase change random access memory: PRAM, or a resistive random access memory: ReRAM).
In the resistance change memory, the change of its resistance value caused by the application of a current (or voltage) is used to determine whether data is “1” or “0”.